Drone spots shark sizing up surfers off Ballina

JUST when you thought it was safe to go back in the water ... off NSW's north coast.

Dramatic footage has emerged of a large great white chasing a surfer off Ballina - before considering launching a vicious attack on his mate.

The terrifying moment was caught by a Department of Primary Industry drone as it hovered over Lighthouse Beach this summer.

The footage shows the hefty predator lurking in shallow water before making a charge at the two surfers, who appear completely unaware of the shark's presence.

One of the surfers catches a wave just as the beast starts its pursuit, taking them out of harm's way.

The shark was spotted at Lighthouse Beach, Ballina.

The shark then turns its attention to the second surfer, whose legs can be seen dangling in the water.

The shark moves very close - apparently considering an attack, before darting away at the last moment.

The state government has been trialling drones to spot sharks off a number of Northern NSW beaches, where 11 shark attacks - including one fatality - have been recorded since 2015.

There have been no reported attacks on the north coast since the government introduced shark net there in late December.

The shark closes in on its potential quarry. Picture: Department of Primary Industries

A number of dangerous sharks have been caught in the nets, including great whites.

But they have also caught "non-target" mammals and fish, including turtles, rays and dolphin

Other footage from the government's drone shows a wide range of marine life off Ballina, including an eagle ray, a shoal of cownose rays, a green turtle and a leopard shark cruising through the pristine green waters.